A new strain of the Koobface worm is spreading across social networking sites including Facebook, MySpace and Bebo.
The malware posts invitations to the friends of infected users inviting them to view a video. The linked website tries to trick prospective marks into believing they need an updated version of Adobe Flash Player plugin to view the clip. The software offered is, of course, loaded with Windows-specific Trojan code. This malware establishes a back-door on compromised Windows machines.
A write-up of the assault, including screenshots, can be found on Trend Micro's website here.
The attack follows the appearance of two rogue applications - "Error Check System" and Facebook closing down - last week which used misleading messages in order to hoodwink users into activating software packages. Neither app spread malware as such but Error Check System has been linked to indirect attempts to attract surfers to sites punting rogue anti-malware (AKA scareware) packages.
Security watchers, such as Rik Ferguson at Trend Micro, responded to the twin threats by urging Facebook to vet applications. Facebook founder Mark Zuckerberg rejected the idea on Monday. "There will occasionally be some applications that people don't like," Zuckerberg told the BBC Newsbeat. "Our philosophy is that having an open system anyone can participate in is generally better."
Facebook spokesman Simon Axten went much further along this path arguing that vetting applications after two problems is like saying "there have been two robberies, we need to implement martial law in the city". More than 660,000 developers write for the platform and only a tiny, tiny percentage are doing anything potentially untoward, he told CNet, adding the site employs a team that investigates applications that behave suspiciously, he added. ®